ObjectiveTo analyze the current status of per⁃ and polyfluoroalkyl substances (PFASs) contamination in animal⁃derived foods in Shanghai and to assess the risk of dietary exposure among local residents, thereby providing a scientific basis for future dietary safety and risk management. MethodsA total of 300 commonly consumed animal⁃derived food samples were collected in Shanghai in 2023 and tested for 17 types of PFASs. Based on local dietary consumption data, the weekly exposure intake (EWI) of four representative PFASs was calculated using the exposure assessment model recommended by Food and Agriculture Organization (FAO) and the World Health Organization (WHO). The calculated EWI was compared with the tolerable weekly intake (TWI) set by the European Food Safety Authority (EFSA) to assess the health risks associated with dietary intake of PFASs. ResultsThe predominant PFASs detected in aquatic products were PFUnDA (98.67%), PFTrDA (98.00%), and PFOS (95.33%), with PFUnDA having the highest median mass fraction (0.378 ng·g^-1). In meat samples, PFBA (54.17%), PFOA (20.83%), and PFOS (18.33%) were mainly detected, with PFBA showing the highest median mass fraction (0.027 ng·g^-1). In egg samples, the most frequently detected compounds were PFBA (90.00%), PFOA (63.33%), PFOS (50.00%), PFDA (50.00%), PFNA (50.00%), and PFHxDA (50.00%), with PFBA again having the highest median mass fraction (0.068 ng·g^-1). The median mass fractions of the four key PFASs (PFOA, PFOS, PFNA, and PFHxS) in aquatic products were significantly higher than those in meat products and eggs (all P<0.001), and there were statistically significant differences in the median mass fractions of the four PFASs among different types of aquatic products (all P<0.05). The EWI of the four PFASs was 2.970 ng·kg^-1 for the mean consumption group and 6.676 ng·kg^-1 for the high consumption group (P₉₅), with females having higher EWI values than males. ConclusionPFOS, PFOA, and PFBA are the major PFAS contaminants in animal⁃derived foods consumed by Shanghai residents, with aquatic products having the highest levels of contamination. The EWIs of four PFASs among Shanghai residents did not exceed EFSA’s recommended TWI at average consumption levels. However, the EWIs for high⁃consumption populations exceeded the EFSA⁃recommended TWI, posing potential health risks to these populations. Aquatic products contribute the most to dietary PFAS exposure. It is necessary to strengthen PFAS monitoring in aquatic products and conduct targeted risk assessments for high⁃consumption groups.

The detection principle of microfluidic microfluidic technology was introduced.The current research status of microfluidic platform-based SARS-CoV-2 nucleic acid detection technologies were reviewed such as reverse transcription quantitative real-time polymerase chain reaction(RT-qPCR),digital PCR,isothermal amplification and clustered regularly interspaced palindromic repeats/CRISPR-associated protein.The deficiencies of microfluidic platform-based SARS-CoV-2 nucleic acid detection were analyzed.It's pointed out microfluidic platform-based SARS-CoV-2 nucleic acid detection had to be optimized and validated clinically in specialty,sensitivity,detection limit,reproducibility,informatization,quality control and reagent cost.[Chinese Medical Equipment Journal,2024,45(1):101-107]

Objective:To investigate the prognosis and the factors that influence it in patients with non-gastric gastrointestinal stromal tumors (GISTs) who are at low risk of recurrence.Methods:This was a retrospective cohort study. Clinicopathologic and prognostic data from patients with non-gastric GISTs and at low risk of recurrence (i.e., very low-risk or low-risk according to the 2008 version of the Modified NIH Risk Classification), who attended 18 medical centers in China between January 2000 and June 2023, were collected. We excluded patients with a history of prior malignancy, concurrent primary malignancy, multiple GISTs, and those who had received preoperative imatinib. The study cohort comprised 1,571 patients with GISTs, 370 (23.6%) of whom were at very low-risk and 1,201 (76.4%) at low-risk of recurrence. The cohort included 799 (50.9%) men and 772 (49.1%) women of median age 57 (16–93) years. Patients were followed up to July 2024. The prognosis and its influencing factors were analyzed. Receiver operating characteristic curves for tumor diameter and Ki67 were established, and the sensitivity, specificity, area under the curve (AUC) and optimal cut-off value with 95% confidence intervals were calculated. Propensity score matching was implemented using the 1:1 nearest neighbor matching method with a matching tolerance of 0.02.Results:With a median follow-up of 63 (12–267) months, the 5- and 10-year overall survival (OS) rates of the 1,571 patients were 99.5% and 98.0%, respectively, and the 5- and 10-year disease-free survival (DFS) rates were 96.3% and 94.4%, respectively. During postoperative follow-up, 3.8% (60/1,571) patients had disease recurrence or metastasis, comprising 0.8% (3/370) in the very low-risk group and 4.7% (57/1,201) in the low-risk group. In the low-risk group, recurrence or metastasis occurred in 5.5% (25/457) of patients with duodenal GISTs, 3.9% (25/645) of those with small intestinal GISTs, 9.2% (6/65) of those with rectal GISTs, and 10.0% (1/10) of those with colonic GISTs. Among the 60 patients with metastases, 56.7% (34/60) of the metastases were located in the abdominal cavity, 53.3% (32/60) in the liver, and 3.3% (2/60) in bone. During the follow-up period, 13 patients (0.8%) died of disease. Receiver operating characteristic curves were plotted for tumor diameter and Ki67 and assessed using the Jordon index. This showed that the difference in DFS between the two groups was statistically significant when the cutoff value for tumor diameter was 3.5 cm (AUC 0.731, 95% CI: 0.670–0.793, sensitivity 77.7%, specificity 64.1%). Furthermore, the difference in DFS between the two groups was statistically significant when the cutoff value for Ki67 was 5% (AUC 0.693, 95% CI: 0.624–0.762, sensitivity 60.7%, specificity 65.3%). Multifactorial analysis revealed that tumor diameter ≥3.5 cm, Ki67 ≥5%, and R1 resection were independent risk factors for DFS in patients with non-gastric GISTs at low risk of recurrence (all P<0.05). Furthermore, age >57 years, Ki67 ≥5%, and R1 resection were also independent risk factors for OS in patients with non-gastric GISTs at low risk of recurrence (all P<0.05). We also grouped the patients according to whether they had received postoperative adjuvant treatment with imatinib for 1 or 3 years. This yielded 137 patients in the less than 1-year group, 139 in the 1-year plus group; and 44 in both the less than 3 years and 3-years plus group. After propensity score matching for age, tumor diameter, Ki67, and resection status, the differences in survival between the two groups were not statistically significant (all P>0.05). The 10-year DFS and OS were 87.5% and 95.5%, respectively, in the group treated with imatinib for less than 1 year and 88.5% and 97.8%, respectively, in the group treated for more than 1 year. The 10-year DFS and OS were 89.6% and 92.6%, respectively, in the group treated with imatinib for less than 3 years and 88.0% and 100.0%, respectively, in the group treated with imatinib for more than 3 years. Conclusion:The overall prognosis of primary, non-gastric, low recurrence risk GISTs is relatively favorable; however, recurrences and metastases do occur. Age, tumor diameter, Ki67, and R1 resection may affect the prognosis. For some patients with low risk GISTs, administration of adjuvant therapy with imatinib for an appropriate duration may help prevent recurrence and improve survival.

Objective:To evaluate the correlation between vascular hyperintensity of magnetic resonance fluid-attenuated inversion recovery (FLAIR) sequence(FVH) and related parameters of magnetic resonance perfusion weighted imaging (MR-PWI) in patients with middle cerebral artery stenosis cerebral infarction, and to explore the hemodynamic factors related to FVH and the effect of FVH on the short-term clinical prognosis of patients.Methods:A total of 116 patients with middle cerebral artery stenosis cerebral infarction in the Department of Neurology, Qingpu Branch of Zhongshan Hospital Affiliated to Fudan University from January 2020 to December 2022 were collected.According to the diagnostic criteria of FVH, they were divided into FVH (+ ) group (78 cases) and FVH(-) group (38 cases). All patients underwent magnetic resonance(MR) and MR-PWI scans.Demographic and cerebrovascular risk factors were collected, clinical neurological function of patients was assessed by national institate of health stroke scale(NIHSS) upon admission and discharge, and cognitive function of patients was assessed by mini-mental state examination (MMSE). Short-term clinical outcome was assessed using modified Rankin scale(mRS) at the 90th day after discharge.The degree of middle cerebral artery stenosis, positive or negative FVH, FVH score, hypoperfusion volume and MR-PWI related parameters, including peak time (Tmax), mean transit time (MTT), cerebral blood volume (CBV) and cerebral blood flow (CBF), were evaluated in relation to clinical symptoms.SPSS 22.0 statistical software was used for t test, Chi-square test and Pearson correlation analysis. Results:There were significant differences in hypoperfusion volume, Tmax, MTT and CBF between FVH (+ ) group and FVH(-) group( t=1.989, 3.830, 5.223, 3.911, all P<0.05). In terms of short-term clinical outcome, the improvement rate of neurological function ((8.25±6.39)%, (12.22±6.08)%) and MMSE score(25.48±1.59), (26.31±1.26) in FVH (+ ) group were significantly lower than those in FVH(-) group, and the number of patients with progressive stroke during hospitalization in FVH(+ ) group was more than that of FVH(-) group(22(28.21%), 4(10.53%)) (all P<0.05). Pearson correlation analysis showed that FVH score was positively correlated with hypoperfusion volume ( r=0.786, P<0.01) and MTT ( r=0.692, P<0.01), and negatively correlated with CBF ( r=-0.568, P<0.01), but no significant correlation with the degree of arterial stenosis ( r=0.363, P>0.05). Conclusion:FVH is closely related to the Tmax, MTT and CBF values shown in MR-PWI, and the incidence of stroke in progression and short-term adverse prognosis are more likely in FVH(+ ) group, suggesting that FVH can be used as a convenient imaging indicator to reflect the hypoperfusion status of patients with middle cerebral artery stenosis cerebral infarction, and can provide an objective basis for further individualized treatment.

Background::Carotid intima-media thickness (IMT) and diameter, stiffness, and wave reflections, are independent and important clinical biomarkers and risk predictors for cardiovascular diseases. The purpose of the present study was to establish nationwide reference values of carotid properties for healthy Chinese adults and to explore potential clinical determinants.Methods::A total of 3053 healthy Han Chinese adults (1922 women) aged 18-79 years were enrolled at 28 collaborating tertiary centers throughout China between April 2021 and July 2022. The real-time tracking of common carotid artery walls was achieved by the radio frequency (RF) ultrasound system. The IMT, diameter, compliance coefficient, β stiffness, local pulse wave velocity (PWV), local systolic blood pressure, augmented pressure (AP), and augmentation index (AIx) were then automatically measured and reported. Data were stratified by age groups and sex. The relationships between age and carotid property parameters were analyzed by Jonckheere-Terpstra test and simple linear regressions. The major clinical determinants of carotid properties were identified by Pearson’s correlation, multiple linear regression, and analyses of covariance.Results::All the parameters of carotid properties demonstrated significantly age-related trajectories. Women showed thinner IMT, smaller carotid diameter, larger AP, and AIx than men. The β stiffness and PWV were significantly higher in men than women before forties, but the differences reversed after that. The increase rate of carotid IMT (5.5 μm/year in women and 5.8 μm/year in men) and diameter (0.03 mm/year in both men and women) were similar between men and women. For the stiffness and wave reflections, women showed significantly larger age-related variations than men as demonstrated by steeper regression slopes (all P for age by sex interaction <0.05). The blood pressures, body mass index (BMI), and triglyceride levels were identified as major clinical determinants of carotid properties with adjustment of age and sex. Conclusions::The age- and sex-specific reference values of carotid properties measured by RF ultrasound for healthy Chinese adults were established. The blood pressures, BMI, and triglyceride levels should be considered for clinical application of corresponding reference values.

Objective:To investigate the prognosis and the factors that influence it in patients with non-gastric gastrointestinal stromal tumors (GISTs) who are at low risk of recurrence.Methods:This was a retrospective cohort study. Clinicopathologic and prognostic data from patients with non-gastric GISTs and at low risk of recurrence (i.e., very low-risk or low-risk according to the 2008 version of the Modified NIH Risk Classification), who attended 18 medical centers in China between January 2000 and June 2023, were collected. We excluded patients with a history of prior malignancy, concurrent primary malignancy, multiple GISTs, and those who had received preoperative imatinib. The study cohort comprised 1,571 patients with GISTs, 370 (23.6%) of whom were at very low-risk and 1,201 (76.4%) at low-risk of recurrence. The cohort included 799 (50.9%) men and 772 (49.1%) women of median age 57 (16–93) years. Patients were followed up to July 2024. The prognosis and its influencing factors were analyzed. Receiver operating characteristic curves for tumor diameter and Ki67 were established, and the sensitivity, specificity, area under the curve (AUC) and optimal cut-off value with 95% confidence intervals were calculated. Propensity score matching was implemented using the 1:1 nearest neighbor matching method with a matching tolerance of 0.02.Results:With a median follow-up of 63 (12–267) months, the 5- and 10-year overall survival (OS) rates of the 1,571 patients were 99.5% and 98.0%, respectively, and the 5- and 10-year disease-free survival (DFS) rates were 96.3% and 94.4%, respectively. During postoperative follow-up, 3.8% (60/1,571) patients had disease recurrence or metastasis, comprising 0.8% (3/370) in the very low-risk group and 4.7% (57/1,201) in the low-risk group. In the low-risk group, recurrence or metastasis occurred in 5.5% (25/457) of patients with duodenal GISTs, 3.9% (25/645) of those with small intestinal GISTs, 9.2% (6/65) of those with rectal GISTs, and 10.0% (1/10) of those with colonic GISTs. Among the 60 patients with metastases, 56.7% (34/60) of the metastases were located in the abdominal cavity, 53.3% (32/60) in the liver, and 3.3% (2/60) in bone. During the follow-up period, 13 patients (0.8%) died of disease. Receiver operating characteristic curves were plotted for tumor diameter and Ki67 and assessed using the Jordon index. This showed that the difference in DFS between the two groups was statistically significant when the cutoff value for tumor diameter was 3.5 cm (AUC 0.731, 95% CI: 0.670–0.793, sensitivity 77.7%, specificity 64.1%). Furthermore, the difference in DFS between the two groups was statistically significant when the cutoff value for Ki67 was 5% (AUC 0.693, 95% CI: 0.624–0.762, sensitivity 60.7%, specificity 65.3%). Multifactorial analysis revealed that tumor diameter ≥3.5 cm, Ki67 ≥5%, and R1 resection were independent risk factors for DFS in patients with non-gastric GISTs at low risk of recurrence (all P<0.05). Furthermore, age >57 years, Ki67 ≥5%, and R1 resection were also independent risk factors for OS in patients with non-gastric GISTs at low risk of recurrence (all P<0.05). We also grouped the patients according to whether they had received postoperative adjuvant treatment with imatinib for 1 or 3 years. This yielded 137 patients in the less than 1-year group, 139 in the 1-year plus group; and 44 in both the less than 3 years and 3-years plus group. After propensity score matching for age, tumor diameter, Ki67, and resection status, the differences in survival between the two groups were not statistically significant (all P>0.05). The 10-year DFS and OS were 87.5% and 95.5%, respectively, in the group treated with imatinib for less than 1 year and 88.5% and 97.8%, respectively, in the group treated for more than 1 year. The 10-year DFS and OS were 89.6% and 92.6%, respectively, in the group treated with imatinib for less than 3 years and 88.0% and 100.0%, respectively, in the group treated with imatinib for more than 3 years. Conclusion:The overall prognosis of primary, non-gastric, low recurrence risk GISTs is relatively favorable; however, recurrences and metastases do occur. Age, tumor diameter, Ki67, and R1 resection may affect the prognosis. For some patients with low risk GISTs, administration of adjuvant therapy with imatinib for an appropriate duration may help prevent recurrence and improve survival.

OBJECTIVE To investigate the effect of Jiawei Tianwang Buxin Dan(JWBXD)on insomnia in rats exposed to simulated high-altitude conditions.METHODS ① Thirty SD rats were randomly divided into the normal control,model,model+Jiawei Tianwang Buxin Dan(JWBXD,9.6 mg·kg-1),model+Tianwang Buxin Dan(TWBXD,9.6 mg·kg-1),and model+diazepam(DZP,3 mg·kg-1)groups.Rats,except for the normal control group,were subjected to a low-pressure,low-oxygen animal experimental chamber simulating a 5000 m altitude.Respective drugs were ig administrated once daily at 9:00 for seven days,and signal acquisition and sleep analysis were conducted by a wireless physiological sig-nal telemetry system.②Forty rats were randomly divided into five groups as described in ①.Through-out the experiment,the general condition and body mass of the rats were observed daily.Drug adminis-tration lasted for seven days,and grip strength was tested one hour after the final administration.ELISA was used to measure the levels of corticotropin-releasing hormone(CRH),adrenocorticotropic hor-mone(ACTH),corticosterone(CORT),and melatonin(MLT)in serum.Western blotting was performed to measure the expression levels of core clock proteins period circadian regulator 2(Per2),circadian locomotor output cycles(Clock),cryptochrome 2(Cry2),brain-muscle arnt-like protein 1(Bmal1),nuclear receptor subfamily 1,group D member 1(NR1D1),glycogen synthase kinase-3β(GSK-3β),as well as acetylserotonin O-methyltransferase(ASMT)in the hypothalamus and pineal gland,respectively.RESULTS ① Compared with the normal control group,the model group exhibited a decrease in total sleep time(P<0.01),an increase in wakefulness(P<0.01),a significant reduction in slow wave sleep(SWS)(P<0.05)and the mean bouts duration(P<0.05).Compared with the model group,both DZP and JWBXD(P<0.01)prolonged sleep time and suppressed wakefulness(P<0.01)in the hypoxic envi-ronment.DZP and JWBXD prolonged SWS(P<0.05,P<0.01),while TWBXD had no significant effect.JWBXD improved the mean bouts duration of SWS in the model rats(P<0.01),whereas no such improvement was observed in model+DZP and model+TWBXD groups.② Compared with the normal control group,the model group showed a significant decrease in forelimb grip strength(P<0.01),increased levels of serum ACTH(P<0.05),CRH,and CORT(P<0.01),and decreased MLT levels(P<0.05).The expression levels of Per2,Cry2,GSK-3β,and NR1D1 in the hypothalamus were downregu-lated(P<0.05,P<0.01),while Bmal1 and Clock were upregulated(P<0.05,P<0.01).ASMT expression in the pineal gland was decreased(P<0.05).Compared with the model group,JWBXD and TWBXD enhanced forelimb grip strength(P<0.01),reduced serum CORT and ACTH levels(P<0.05),decreased CRH levels(P<0.01),and restored MLT levels(P<0.01).JWBXD upregulated the expression levels of Per2,Cry2,GSK-3β and NR1D1 in the hypothalamus(P<0.05,P<0.01),but downregulated Bmal1 and Clock expression(P<0.05,P<0.01).TWBXD downregulated Bmal1 expression in the hypothalamus(P<0.01)and increased NR1D1 expression(P<0.05).DZP significantly enhanced the expression levels of Per2,Cry2 and NR1D1 in the hypothalamus(P<0.01).JWBXD,TWBXD and DZP improved ASMT expression in the pineal gland(P<0.05).CONCLUSION JWBXD can improve sleep structure and prolong the duration of SWS in rats exposed to simulated high-altitude conditions.The mechanisms may involve the regulation of core clock protein expressions in the hypothalamus,promotion of mela-tonin secretion,and inhibition of HPA axis hyperactivity.

Objective:To analyze regional differences in MMACHC gene variations among patients with cblC-type methylmalonic acidemia (MMA) in China and to explore the relationship between these variations and neonatal screening, biochemical markers and prognosis.Methods:Retrospective case summary. Clinical and laboratory data, including general condition, biochemical markers and genetic analysis, were collected from 1 859 cblC MMA patients from 2005 to 2023. Patients were divided into 7 groups according to their regions: north China, northeast China, east China, central China, south China, southwest China and northwest China. They were also classified into neonatal screening and non-neonatal screening groups. Mann-Whitney U and Kruskal-Wallis tests were used to compare biochemical marker levels. In contrast, the Chi-square test was applied to compare MMACHC gene variant frequencies, neonatal screening proportion, onset age and prognosis between groups. Results:Among 1 859 cases of cblC MMA, 1 019 were male and 840 were female, with a consultation age of 1.0 (0.1, 5.0) month. A total of 1 787 cases carried compound heterozygous or homozygous variants and only 1 variant site was identified in 72 cases. The 10 most frequent variants were c.609G>A (1 238 cases), c.658_660delAAG (343 cases), c.80A>G (284 cases), c.482G>A (239 cases), c.567dupT (191 cases), c.656_658delAGA (131 cases), c.217C>T (109 cases), c.394C>T (105 cases), c.445_446delTG (51 cases) and c.1A>G (50 cases). The frequency of the c.609G>A was the lowest in northwest China (28.8% (44/154), χ2=-18.42, P<0.05). The frequency of the c.567dupT was the most common in southwest China (25.0% (20/80), χ2=71.70, P<0.001) and c.656_658delAGA had the highest frequency in northeast China (9.3% (19/205), χ2=32.08, P<0.001). Non-missense variants (91.2% (62/68), 88.5% (46/52)) and early-onset patients (90.0% (36/40), 94.4% (34/36)) were both more prevalent in southwest and south China ( χ2=14.95, 31.69, both P<0.05). The proportion of neonatal screening was the lowest in south China (22.2% (8/36), χ2=98.48, P<0.05), where the mortality rate was the highest (19.1% (4/21), χ2=38.98, P<0.001). East China exhibited the highest frequency of missense variants (21.5% (339/1 579)), the highest proportion of patients identified through neonatal screening (54.5% (465/853)), and a more significant proportion of patients with good prognosis (36.6% (227/621), χ2=14.57, 93.49, 38.98, all P<0.05). In addition, the c.482G>A variant was more frequent in patients diagnosed by neonatal screening compared to those diagnosed by other methods (8.3% (132/1 586) vs. 5.9% (122/2 060), χ2=7.97, P<0.05). Conclusions:The frequency of MMACHC gene variation varies across different regions. The c.609G>A was least frequent in northwest China, c.567dupT was most common in southwest China, and c.656_658delAGA was most prevalent in northeast China. South China had the lowest neonatal screening rate and the highest mortality. At the same time, east China exhibited the highest frequency of missense variants, the highest proportion of patients identified through neonatal screening and the best prognosis. The c.482G>A variant was more frequent in patients diagnosed by neonatal screening compared to those diagnosed by other methods.

Traumatic supraorbital fissure syndrome (TSOFS) is a symptom complex caused by nerve entrapment in the supraorbital fissure after skull base trauma. If the compressed cranial nerve in the supraorbital fissure is not decompressed surgically, ptosis, diplopia and eye movement disorder may exist for a long time and seriously affect the patients′ quality of life. Since its overall incidence is not high, it is not familiarized with the majority of neurosurgeons and some TSOFS may be complicated with skull base vascular injury. If the supraorbital fissure surgery is performed without treatment of vascular injury, it may cause massive hemorrhage, and disability and even life-threatening in severe cases. At present, there is no consensus or guideline on the diagnosis and treatment of TSOFS that can be referred to both domestically and internationally. To improve the understanding of TSOFS among clinical physicians and establish standardized diagnosis and treatment plans, the Skull Base Trauma Group of the Neurorepair Professional Committee of the Chinese Medical Doctor Association, Neurotrauma Group of the Neurosurgery Branch of the Chinese Medical Association, Neurotrauma Group of the Traumatology Branch of the Chinese Medical Association, and Editorial Committee of Chinese Journal of Trauma organized relevant experts to formulate Chinese expert consensus on the diagnosis and treatment of traumatic supraorbital fissure syndrome ( version 2024) based on evidence of evidence-based medicine and clinical experience of diagnosis and treatment. This consensus puts forward 12 recommendations on the diagnosis, classification, treatment, efficacy evaluation and follow-up of TSOFS, aiming to provide references for neurosurgeons from hospitals of all levels to standardize the diagnosis and treatment of TSOFS.

Objective:To analyze the effectiveness and interobserver agreement of the Parer five-tier, the National Institute of Child Health and Human Development (NICHD) three-tier, and the International Federation of Gynecology and Obstetrics (FIGO) three-tier electronic fetal monitoring (EFM) systems in identification of neonatal acidosis during labor.Methods:This retrospective study was conducted on full-term singleton cephalic deliveries with neonatal acidosis (umbilical artery blood gas pH≤7.1) and normal newborns (umbilical artery blood gas pH≥7.2) in the Nanjing Drum Tower Hospital, Nanjing University Medical School from January to December 2020. EFM tracings during the last 30-60 min before delivery were collected. Four obstetricians independently described the features of randomly sorted and coded EFM tracings. Another obstetrician categorized these tracings using the NICHD three-tier, FIGO three-tier, and Parer five-tier evaluation systems based on the features. All researchers were masked to the clinical characteristics and maternal and neonatal outcomes. The sensitivity and specificity for identifying neonatal acidosis, as well as the interobserver agreement, were analyzed for all three systems. Independent sample t-test, Chi-square (or Fisher's exact test) and Mann-Whitney U tests were used for statistical analysis. Inter-group comparisons of sensitivity and specificity between the three evaluation systems were assessed using McNemar's test. The Kappa statistic was used to analyze interobserver agreement. Results:This study included a total of 3 558 cases. After propensity score matching, there were 44 cases of neonatal acidosis and 78 control cases. There were no significant differences in parity, gestational weeks, modes of delivery, placental abruption, or analgesia rates between the two groups. The rates of instrumental vaginal delivery and neonatal intensive care unit (NICU) admission in the acidosis group were significantly higher than those in the control group [15.8% (7/44) vs. 2.6% (2/78), χ2=8.45, P=0.003; 31.8% (14/44) vs. 12.8% (10/78), χ2=8.45, P=0.004], while the umbilical artery blood pH and mean base excess were lower in the acidosis group than in the control group [7.04±0.07 vs. 7.30±0.05, t=4.98; (－12.40±3.32) vs. (－5.64±1.95) mmol/L, t=13.61; both P<0.001]. (2) Using the NICHD three-tier system, 95.5% (42/44) of the acidosis cases and 89.7% (70/78) of the control cases were classified as having category Ⅱ EFM tracings, indicating potential fetal acid-base imbalance; category Ⅲ EFM tracings were only observed in 4.5% (2/44) of the cases in the acidosis group. With the FIGO three-tier system, 81.8% (36/44) of the acidosis cases were categorized as having "pathological" tracings, and with the Parer five-tier system, 86.4% (38/44) of the acidosis cases were correctly classified into the "orange or red" risk zones that indicated acid-base imbalance. Among the control cases, there were 28.2% (22/78) with EFM tracings of "normal patterns" categorized by the FIGO three-tier system, and 41.0% (32/78) classified into the "green or blue" risk zones by the Parer five-tier system, which indicated good fetal conditions. None of the acidosis cases were misdiagnosed as being normal by the Parer five-tier system. (3) Compared with the NICHD three-tier system, both the FIGO three-tier and the Parer five-tier systems showed increased diagnostic sensitivity [4.5% (1.2%- 14.5%) vs. 81.8% (66.8%-89.4%) and 86.4% (71.8%-92.4%)], but decreased specificity [100.0% (95.3%- 100.0%) vs. 87.2% (78.0%-92.9%) and 84.6% (75.0%-91.0%)]. There was no statistically significant difference in the sensitivity or specificity between the FIGO three-tier and Parer five-tier systems for identifying neonatal acidosis ( P=0.727 and 0.791). (4) When reading the tracings of control cases, the total agreement rate for the NICHD three-tier system by different observers was as high as 94.2%, while the total agreement rates for the FIGO three-tier and Parer five-tier systems were 69.7% and 67.7%, respectively. In the interpretation of EFHR tracings for acidosis cases, the interobserver agreement for the Parer five-tier system was excellent [Kappa (95% CI): 0.87 (0.79-0.95)], while both the NICHD three-tier and FIGO three-tier systems showed good agreement [Kappa (95% CI): 0.77 (0.66-0.88) and 0.72 (0.60-0.84)]. Conclusions:The Parer five-tier and the FIGO three-tier systems have higher sensitivity in identifying neonatal acidosis than the NICHD three-tier system, and the Parer five-tier system achieves a higher negative predictive value and a greater agreement in the interpretation of pathological EFM patterns.